Inking cylinder



Sept 3 1964 G. J. ZAHRADNIK 3,147,697

INKING CYLINDER Filed 001). l0, 1961 FIG.

INVENTR. George J.' Zakradmk United States Patent O 3,147,697 INGCYLINDER George I. Zahradnik, North Riverside, Ill., assignor to A. B.Dick Company, Chicago, Ill., a corporation of Illinois Filed Oct. 10,1961, Ser. No. 144,121 4 Claims. (Cl. 101-119) This invention relates toimprovements in inking cylinders such as the type of cylinders which areemployed in stencil duplicating machines.

In inking cylinders which are employed in mimeograph operations, thecylinder is filled with ink which is adapted to pass throughperforations in the cylinder onto an inking pad. During a duplicatingcycle, the ink is adapted to pass from the pad through stencil openingsin an adjacent stencil and then to a sheet to be printed.

On many occasions ink remains in the cylinder during periods of nonuseand leaking and dripping of ink has been a problem. The ink will, insome instances, seep into the ink pad and over the cylinder edges, evenwhere the cylinder is positioned with the perforated side up. Thesituation is particularly noticeable where high humidity conditions areexperienced.

There are other occasions where an ink pad becomes saturated with ink orWhere the ink otherwise leaks from the cylinder and rolls down. It willbe obvious that the presence of ink on the mechanisms below the cylinderis undesirable and it is extremely difficult to accomplish cleaning inthis area of the machine.

It is, therefore, an object of this invention to provide an improvedinking cylinder which is not subject to the problems of roll-down andleakage of ink.

It is a further object of this invention to provide an improved inkingcylindeiwhich includes means for collecting ink which tends to roll downfrom the cylinder and leak into the housing of the duplicating machine.

These and other objects of this invention will appear hereinafter andfor purposes of illustration, but not of limitation, specificembodiments are shown in the accompanying drawings in which* FIGURE l isa cross-sectional view of an inking cylinder provided with theimprovements of this invention;

FIGURE 2 is a perspective view of an absorbent pad adapted for use inaccordance with this invention;

FIGURE 3 is a detail sectional view of ink collecting means which areincorporated with the inking cylinder for achieving the objects of thisinvention; and

FIGURE 4 is a fragmentary sectional view taken about the line 4 4 ofFIGURE l.

The concepts of this invention provide improvements in inking cylindersof the type which include a cylindrically curved, perforated portion fortransfer of the ink from the cylinder reservoir to the ink pad.Elongated slots are formed in the cylinder adjacent the ends of theperforated portion for receipt of ink which tends to pass beyond theends of the perforated portion and roll down into the mechanisms below.

The slots formed in the cylinder surface open into an ink collectingchamber which extends within the cylinder and outlets are provided inthe chamber for passage of ink back into the ink reservoir. In apreferred form of the invention means are provided within the chamberfor facilitating the passage of ink into the chamber. Such means, whichmay take the form of an absorbent pad or means having a capillary actionwith respect to the ink, are provided for contact with the ink pad toinsure passage of the ink in the desired manner.

The accompanying drawings and the following related explanation willprovide a more specific description of the inventive concepts. FIGURE 1illustrates in crosssection an inking cylinder having an ink tank orreser- 3,147,697 Patented Sept. 8, 1964 ICC voir 12 and a cylindricallycurved portion 14. Perforations 16 are provided in the curved portionfor passage of ink to an ink pad 18 which in turn will transmit inkthrough openings in a stencil 20 to produce copy.

The stencil and ink pad may be secured to the cylinder in any suitablemanner. For example, the stud 22 and the guide pin 24 may serve toprovide tensioning means of the type described in the United Statespatent to DuBois No. 2,916,990, issued December l5, 1959.

Slots 26 are formed in the drum surface adjacent the ends of theperforated portion 14. The slots extend transversely of the cylinder andopen into ink collecting chambers 28. Openings 30 are provided at theends of the transversely elongated chamber for transferring inkcollected into the cylinder reservoir.

In a preferred form of the invention there are provided within thechambers 28 means 32 for absorbing or otherwise aiding in the collectionof ink. The means 32 can be composed of any material capable ofcollecting the ink from the pad 13 and aiding in transferring the inkback into the ink reservoir. For example, the felt pad shown in FIGURE 2can comprise the means 32, the felt serving to absorb any ink soakingthrough the ink pad and tending to drip over the edges of the cylinder.It Will be noted that the edge 34 of the pad is tapered whereby thisedge will be flush with the surface of the cylinder. With this designthe ink pad will directly contact the means 32 and more eflicientdrawing of ink into the chamber will be accomplished. Speciic examplesof suitable felt composions include white felt, designated American FeltNo. 51,018 and gray-black felt, designated Rhopac No. 30,103.

Various other means can be employed for aiding in drawing ink into thechamber 28. These means can be porous compositions adapted to absorb theink or they may include various laminated constructions having passagesbetween the laminations for drawing in the ink by capillary action.Thus, corrugated materials can be laminated to provide suitable passagesor a plurality of closely spaced straw-like members with capillarypassages could be employed.

Additional more specific examples of suitable ink collecting meansinclude laminated olf-set clean-up materials and laminated blottermaterial, such constructions providing an absorbing as Well as acapillary action in use. Various open cell foam materials havinginterconnected pores include 5 pound charcoal polyurethane foam, 45 porepolyurethane foam and l0 pore polyurethane foam.

The ink collecting means disposed in the chamber 2S can also be formedfrom a laminated plastic labyrinth employing various plasticcompositions. E flute corrugated cardboard constructions are also usefulfor this purpose since the construction will provide a plurality ofsmall passages through the chamber 28 whereby the ink will pass into thechamber by means of capillary action. A similar result is obtained whena plurality of vertically aligned straws, preferably relatively smallstraws with small passages, are used to make up the ink collectingconstruction. In any event, constructions which are formed from thevarious materials set forth or from equivalent materials should bedesigned so that the exposed end of the construction will be flush withthe periphery of the cylinder whereby contact with the pad 18 isachieved.

The inking cylinders which are modified in accordance with thisinvention has been operated over long periods without significantroll-down or leakage. Cylinders of the improved type described have beentested under the most adverse conditions of humidity withoutexperiencing the objectionable leakage. Ink pads, when provided oncylinders of the improved type, readily give up the ink which saturatesthem after a printing operation to the collecting means of thisinvention, and the ink is thus passed into the cylinder reservoirwithout dripping onto other parts of the printing mechanism. y

It will be understood that various modifications may be made in theabove described inking cylinders which provide the characteristics ofthis invention without departing from the spirit thereof, particularlyas dened in the following claims.

I claim:

l. In an inking cylinder for a rnimeograph machine in which the inkingcylinder includes a rigid cylindrical curved perforated portion and anink pad extending continuously over said curved portion and secured atthe ends thereof to the inking cylinder, the improvement comprising anattachment secured to the underside of the inking cylinder adjacent theends of said curved portion to define an enclosed collecting chambertherebetween, elongate slots extending through the end portions of thecurved portion into communication with said chambers for passage of inkthrough said cylinder into said charnbers, openings in said attachmentcommunicating the chamber with the ink well within said inking cylinderfor passage of ink from the chamber into the ink well, and an absorbentmember lling the chamber for drawing ink from the cylinder into thechamber through said slots, said rigid cylindrical curved portion of thecylinder extending beyond the chambers to provide a continuous rigidsupport for the portions of the ink pad overlying the chambers.

2. An inking cylinder according to claim l wherein said collecting meanscomprise felt pads.

3. An inking cylinder according to claim l wherein said collecting meanscomprise laminated pads.

4. An inking cylinder according to claim l wherein said collecting meanscomprise an open cell foam material.

References Cited in the le of this patent UNITED STATES PATENTS2,612,834 Sherman Oct. 7, 1952 FOREIGN PATENTS 402,240 Great BritainNov. 30, 1933

1. IN AN INKING CYLINDER FOR A MIMEOGRAPH MACHINE IN WHICH THE INKINGCYLINDER INCLUDES A RIGID CYLINDRICAL CURVED PERFORATED PORTION AND ANINK PAD EXTENDING CONTINOUSLY OVER SAID CURVED PORTION AND SECURED ATTHE ENDS THEREOF TO THE INKING CYLINDER, THE IMPROVEMENT COMPRISING ANATTACHMENT SECURED TO THE UNDERSIDE OF THE INKING CYLINDER ADJACENT THEENDS OF SAID CURVED PORTION TO DEFINE AN ENCLOSED COLLECTING CHAMBERTHEREBETWEEN, ELONGATE SLOTS EXTENDING THROUGH THE END PORTIONS OF THECURVED PORTION INTO COMMUNICATION WITH SAID CHAMBERS FOR PASSAGE OF INKTHROUGH SAID CYLINDER INTO SAID CHAMBERS, OPENINGS IN SAID ATTACHMENTCOMMUNICATING THE CHAMBER WITH THE INK WELL WITHIN SAID INKING CYLINDERFOR PASSAGE OF INK FROM THE CHAMBER INTO THE INK WELL, AND AN ABSORBENTMEMBER FILLING THE CHAMBER FOR DRAWING INK FROM THE CYLINDER INTO THECHAMBER THROUGH SAID